The present invention relates to gas lasers, and particularly to the type of gas lasers which includes a gas resonant chamber and also a gas reservoir for regenerating the gas in the resonant chamber.
Early gas lasers, particularly of the carbon dioxide type, included an arrangement for circulating the gas through the tube from a gas reservoir externally of the tube in order to regenerate the gas within the tube. Later constructions included a gas reservoir within the tube, but in such constructions care had to be exercised to avoid creating a discharge in the gas reservoir. One construction of the latter type provided a glass helix at one end of the laser tube connecting the gas reservoir to the resonant chamber, and thereby increasing the length of the pathway from the reservoir to the resonant chamber. However, forming the glass helix within the laser tube is complicated and costly. Moreover, even such a construction tends to produce a discharge in the gas reservoir particularly when the laser is operated in the "super pulse" mode, wherein a high voltage is applied to obtain high peak currents for short durations. A further disadvantage of the helical construction is that the cross-section of the regeneration path (helix) is relatively small, and therefore the gas recovery time is relatively long; that is, it may be necessary to wait a few minutes between laser discharges particularly when the laser is operated in the "super pulse" mode.